120 



ARMATURE CONSTRUCTION 



this commutator is built on an armed spider, which is subse- 

 quently mounted on an extension of the armature spider a plan 



FIG. 137. Large Finished Commutator. Dick, Kerr & Co. 



which is frequently used in large commutators. A photograph 

 of a commutator built on these lines is shown in Fig. 137. In 

 connection with the mica V-rings, it may be noted that there is 

 a difference between their arrangement in Figs. 135 and 136. 



